Road Trip Cost Splitter implementation

Binding contract

This record describes what an executable surface must bind and validate. It does not claim that a public calculator, package, or production route is deployed.

Record owner

Guth Instruments

Lifecycle

verified-clean

Evidence ID

t4-115

Effect

Computation or source lookup only

Input and validation requirements

The equal-split formula is undefined when num_people is zero. The mileage-weighted formula also requires a nonzero total_miles; zero total mileage would create another undefined division.

Required corrections

No binding erratum is attached to this unique-name record. Implementers must still preserve the declared units, domain, and failure behavior.

Inspectable interface fixture

The sample below is evidence for interface and validation tests, not a production implementation.

{
  "inputs": {
    "mode": "equal",
    "total_cost": 120,
    "currency": "USD",
    "num_people": 4
  },
  "expected_outputs": {
    "amount_owed_per_person": [
      30,
      30,
      30,
      30
    ]
  },
  "working": "per_person = total_cost / num_people = 120 / 4 = 30. Each of the 4 passengers owes $30."
}

Other records

Sources and evidence

These pointers bind the page to evidence. They do not grant authority or collapse verification into deployment.

• VERIFIED_LEDGER.json
• evidence-tranche4/tranche4-results.json